Ordinate
Returns the y coordinate of a point or the y length of a vector.
ordinate(point) or ordinate(vector)
Example:
ordinate(GA) returns the y-coordinate of the point A.
Coordinates
Given a vector of points, returns a matrix containing the x- and y-coordinates of those points. Each row of the
matrix
denes one point; the rst column gives the x-coordinates and the second column contains the y-
coordinates.
coordinates([point1, point2, …, pointn]))
Equation of
Returns the Cartesian equation of a curve in x and y, or the Cartesian coordinates of a point.
equation(curve) or equation(point)
Example:
If GA is the point at (0, 0), GB is the point at (1, 0), and GC is dened as circle(GA, GB-GA), then
equation(GC) returns x2 + y2 = 1.
Parametric
Works like the equation command, but returns parametric results in complex form.
parameq(GeoObj )
Polar Coordinates
Returns a vector containing the polar coordinates of a point or a complex number.
polar_coordinates(point) or polar_coordinates(complex)
Example:
polar_coordinates(√2, √2) returns [2, π/4]
Measure
Distance
Returns the distance between two points or between a point and a curve.
distance(point1, point2) or distance(point, curve)
Examples:
distance(1+i, 3+3i) returns 2.828… or 2√2.
If GA is the point at (0, 0) and GB is dened as plotfunc(4–x^2/4), then distance(GA, GB) returns 3.464…
or 2√3.
Geometry functions and commands 201
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